Rotary pump



ROTARY PUMPl vFiled Dc. 29. 1956 FIGA; Fles Plas FIGB v NVENTOR: ADoLF lARGEBOER- ATTQRNE/KS Patented Sept. 7, 1937 PATENT OFFICE.

' no'rnnr PUMP 4Adolf Bargeboer, The Hague, Netherlands, as-

signor of a part interest to Machinefabriek- Gebr. Stork & Co. N. V.,Hengelo (0), Netherlands, a Dutch manufacturing company ApplicationDecember 29, 1936, Serial No. 118,043`

In the Netherlands November 16, l1935 9 Claims. (Cl. 23o-79) Thisinvention relates to rotary pumps, more especiallyrotary air pumps ofthe type, which comprises, in combination with a revolubie bladed rotor,a pump chamber having an outlet port, an inlet port or a plurality ofinlet ports arranged laterally of said rotor and extending through lessthan 180", and a guide or working channel provided radially outside therotor and open only on the side facing the rotor, the inner wall of thepump chamber having, between-the outlet` port and the inlet port(considered in the directin of rotation), a segmental portion tting therotor with the least possible clearance so as to form a seal.

In a pump of this known type, the pressure increases in the directionfrom the inletl or suction port towards tne outlet or delivery port, andthe capacity of the pump to produce this pressure is generallyattributed to the action of a water ring, which, on the suction side, isexpelled from the rotor cells under centrifugal force and, on thedelivery side, is forced again to .enter the cells,

thus creating both the partial vacuum required for the suction and theoverpressure required for the delivery. I

Actual tests have now revealed the fact that this explanation of theoperation of pumps of this type is Vnot correct and that the energysupplied and absorbed by the water during said radial movement is ofminor importance and is, `for the greater part, lost-by friction.

The' inventor has found that the operation of the pump is due to acontinuous increase of the energy accumulated in the water, owing' tothe rotor blades throwing the retarded water, at full circumferentialspeed, from the cells into the guide or working channel, wherein thewater gives off its energy and whence it returns into the cells with acertain amount of retardation.

Reference is had to Fig. 1 of the annexed drawing, in which saidadditional movement oi the water is indicated by arrows.

Consequently, there is no question of a relatively quiet, revolvingwater ring. On the ccntrary, a rather violent interaction takes placebetween the water in the guide channel and that in the various rtorcells. This interaction involves considerable\energy losses, whichaccount for the low eciency and the unsatisfactory pumping action, viz.essential reduction of the capacity with increasing delivery pressure.

The object of my invention ris to'impart the indispensable supply ofenergy to the water ring in a novel and improved manner, so that thewater eddies, which are located pa. tly inside and partly outside therotor cells, are caused to whirl about tangentially, and notand at leastnot exclusively-about axially directed axes.v With this object in view,I propose to arrange the outer edges of the rotor blades in non-parallelrelation with the rotor axis. Stated in other language, those edgesof... the blades, which are located in the circumference of the rotor,are composed of portions ,that are unequally spaced from the axis ofrotation.

It goes without saying that between the outlet port and the inlet port,considered in the direction of rotation, the walls of the casing shouldfit the profile of the blades with the least possible clearance and thusprovide for the required sealing between said ports. f

This apparently-insignificant modification of the known constructionresults in a considerable improvement as regards the eiiiciency and the,pumping action.

In order that my said invention may be more fully understood, referenceis had to the drawing, in which:

Fig. 1 isa diagrammatic side view of a bladed rotor of knownconstruction, as referred to hereinbefore,

Fig. 21s an axial sectional elevation of a rotary pump in accordancewith my invention,

provided with ball bearings 2, 2 for the shaft 3. 40

Secured to said bracket .by means of bolts 4 is a casing 5, which isprovided, in addition to the deliverynozzle 9 and the suction nozzle I0,with a vertical partition 5B isolating said nozzles from one another.

Connected to the casing 5, by bolts II, is the pump chamber proper,'which chamber is composed of a at disk 6 provided with an loutlet portI3 and an inlet port I4, an annulus I having an enlarged top portion,and a flat cover 8 forming 50 a bearingfor the shaft 3. Keyed upon thisshaft for rotation within-said chamber is the bladed rotor I5. s

Between the inlet port I4 and the outlet port I3, the circumferentialinner wall of the pump chamber is radially spaced from the substantiallyradial outer edges of the rotor blades so as to define a circumferentialguide channel extending around part of the rotor, but the inner -5 wallof the top portion of the annulus 1, i. e. of the portion extendingbetween the outlet port I3 and the inlet port ,just suiliciently clearsthe rotor to allow the same to freely revolve.

Each rotor blade is provided with a rectangular radial projection II onits outer end, the

top portion of the annulus 'I having a corresponding circumferentialgroove, the inner wall of which snugly ts the lateral edgesof saidprojection.

In the embodiment shown in Fig. 4, each blade has two trapeziformprojections.

Fig. 5 shows an embodiment, in which the rotor blades are encircled bytwo straps or rings I1, i8, each having a plurality ofradial projectionsI9, 20. It will be understood that these projections may be locatedeither in the radial planes of the blades, or intermediate said planes.

In Fig. 6, the radial edges of the blades are arcuate.

Fig. 7 illustrates a pump in which the action of the radial projectionsof the blades is imf proved by a special shape of the circumferentialinner wall of the pump chamber, i. e. 'of the annulus 1. As shown, thiswall in axial section is not bounded by a straight line, but by a curvedand broken line, which is more or less the reflected image of the outerblade edge, so as to denne two shallow grooves 2i and 22 injuxtaposition.

In accordance with Fig. 8, the action of the bladed rotor is improved bythe fact that the 'circumferential wall of the guide or working channel,which in axial section may be straight, broken or curved, is corrugated(instead of circular) in a section at right angles to the axis.

In the pump illustrated inFigs. 9 and 10, the radial projections-of theblades are made inoperative i'n the regions of the inlet and outletv,ports by reason that the circumferential wall of the guide or workingchannel is provided, in said regions; with ridges for sealing thelateral edges of said projections. These ridges may extend through thefull circumferential lengths of said ports, or through only a portionthereof.

I t may also be added that part of the guide channel may be locatedlaterally of the rotor,

instead of exclusively radially outside the same.

What I claim is:

.1. In a pump, more especially an air pump.' a

-rotor mounted for rotation about an axis and provided with blades, theouter edges of which are innen-parallel relation with said axis, 'a pumpchamber enclosing the bladed rotor, an inlet port provided in thechamber laterally of the rotor and extending through less than half thecircumference thereof, an outlet .port provided in the chamber laterallyof the rotor and extending through less than half the circumferencethereof, an inner wall portion of the casing between the outlet port andthe -inlet port formed to seal the rotor. and a working channel portionprovided in the chamber disposed radially outside the rotor' between theinlet port -and the outlet port and open only on the side facing therotor.

2. In a pump as claimed in claim 1, the feature that the outer edges ofthe blades have broken outlines.

3. In a pump as claimed in claim 1, the feature that the outer edges ofthe blades are curved.

4. In a pump as claimed in claim l, the feature that the outer edge ofeach blade is provided with a substantially radial projectioncooperating with the guide channel portion and the seal formed by theinner wall portion.

5. In a pump as claimed in claim l. the feature that the blades areencircled by' a ring provided with radial projections.

6. In a pump as claimed in claim 1, the feature that the circumferentialwall of the guide channel is corrugated in a section at right angles tolthe axis.

'1. AIn a pump as claimed in claim l, the feature that the outer edge ofeach vblade is provided with a substantially radial projection and thatthe circumferential wall of the guide channel is provided, in the regionof Aa port, with circumferential ridges adapted to seal the lateraledges of said projections.

8. In a pump aceording'to claim 1, the feature that the outer edge ofeach blade is pro vided with a radial projection ofpredetermined shapeadapted to cooperate with the sealof the inner wall portion, and thechannel portion has a predetermined form.

9. In a pump according to claim 1, the feature of having the outer edgesof the blades carrying a plurality of spaced radial mojections cooper-Annul' nai-ramona.

